JP2017066282A - Water-stopping sealant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-stopping sealant which has sufficient adhesion between foam and a surface coating film on the foam surface and has a high water-stopping property.SOLUTION: Provided is a water-stopping sealant comprising resin foam and a surface coating film disposed on at least one surface of the resin foam. The surface coating film is a cured product of a photopolymerization reaction between a urethane prepolymer having a plurality of groups of at least one kind selected from a vinyl ether group, allyl ether group, or acrylate group, and a polythiol having a plurality of thiol groups. An average number of functional groups of the polythiol is 2.5 or more, and a ratio of the total number of equivalents of the thiol groups possessed by the polythiol relative to the total number of equivalents of the vinyl ether groups, allyl ether groups, or acrylate groups possessed by the urethane prepolymer is 0.7 to 2.3.SELECTED DRAWING: None

Description

  The present invention relates to a water-proof sealing material.

  Conventionally, as a water-proof sealing material between two objects, it is composed of a urethane foam surface provided with a moisture-curing adhesive layer (Patent Document 1) or a urethane acrylate cured product cured by ultraviolet irradiation on the surface of the urethane foam. There is one provided with a skin layer (Patent Document 2).

However, a product provided with a moisture-curing adhesive layer takes time to complete the reaction, and is inferior in productivity.
In addition, when the surface of the urethane foam is provided with a skin layer composed of a urethane acrylate cured product cured by ultraviolet irradiation, a curing failure due to oxygen occurs during the formation of the urethane acrylate cured product, and the skin layer and the urethane foam are sufficiently Adhesion may not be obtained and high water stop performance may not be obtained.

JP-A-9-183963 JP 2010-1409 A

  The present invention has been made in view of the above points, and has an object to provide a water-stopping sealing material that has sufficient adhesion between the surface coating provided on the surface of the foam and the foam and has a high water-stopping property. To do.

  The present invention relates to a water-proof sealing material comprising a resin foam and a surface coating provided on at least one side of the resin foam, wherein the surface coating is selected from the group of vinyl ether groups, allyl ether groups, and acrylate groups. In addition, a photopolymerization reaction cured product of a urethane prepolymer having a plurality of at least one and a polythiol having a plurality of thiol groups, wherein the average functional group number of the polythiol is 2.5 or more, and the total number of thiol groups the polythiol has The ratio of the urethane prepolymer to the total number of equivalents of the vinyl ether group, allyl ether group, and acrylate group is 0.7 to 2.3.

  The urethane prepolymer preferably has a weight average molecular weight of 2000 to 30000. The elongation of the surface coating is preferably 100% or more.

  According to the present invention, the surface coating provided on at least one surface of the resin foam has a urethane prepolymer having a plurality of at least one selected from the group of vinyl ether groups, allyl ether groups, and acrylate groups, and a plurality of thiol groups. It is a photopolymerization reaction cured product with polythiol having an average functional group number of 2.5 or more and a total equivalent number of thiol groups possessed by the polythiol, the vinyl ether group, allyl ether group, acrylate of the urethane prepolymer. When the ratio of the group to the total equivalent number is 0.7 to 2.3, the adhesiveness between the resin foam and the surface coating on the surface of the resin foam is sufficient, and a water-stopping sealing material having a high water-stopping property is obtained. can get.

It is a front view which shows the test piece for a water-stop test. It is a figure which shows the state at the time of a water-stop test.

Hereinafter, embodiments of the present invention will be described. The water-stop sealing material of the present invention is compressed between members and used to prevent water leakage between the members.
The water-stop sealing material of the present invention comprises a resin foam and a surface coating provided on at least one surface of the resin foam.

  The resin foam is not particularly limited, and an elastic foam is preferable. For example, a polyurethane foam, a polyolefin foam, etc. are mentioned. Among them, polyurethane foam is preferable because it has physical properties suitable as a water-proof sealing material, such as low compression set. In particular, a soft polyretane open-cell foam excellent in flexibility is more preferable because it is easy to make the water-stopping sealing material conform to the surface shape of the water-stopping portion. This open-celled foam preferably has water repellency, low air permeability and a fine cell structure. Although the thickness of the said resin foam is suitably set according to the location etc. to which a water-stop sealing material is attached, 1-30 mm is mentioned as an example.

  The surface film is made of a photopolymerization reaction cured product by an enethiol reaction of a urethane prepolymer having a plurality of at least one selected from the group of vinyl ether groups, allyl ether groups, and acrylate groups, and a polythiol having a plurality of thiol groups.

  A urethane prepolymer having a plurality of at least one selected from the group of vinyl ether groups, allyl ether groups, and acrylate groups is a urethane prepolymer synthesized from a polyol and a polyisocyanate, and from a group of vinyl ether groups, allyl ether groups, and acrylate groups. It is obtained by adding a compound having at least one selected.

The polyisocyanate has two or more isocyanate groups in one molecule, and may be any of aromatic, alicyclic, and aliphatic groups. These may be used alone or in combination. For example, bifunctional polyisocyanate 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′- Diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′- Aromatics such as biphenylene diisocyanate, shiku Alicyclic ones such as hexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, methylcyclohexane diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate And aliphatic compounds such as lysine isocyanate.

  Trifunctional or higher polyisocyanates include 1-methylbenzole-2,4,6-triisocyanate, 1,3,5-trimethylbenzole-2,4,6-triisocyanate, biphenyl-2,4,4. '-Triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2', 5,5 'tetraisocyanate, Examples thereof include triphenylmethane-4,4 ′, 4 ″ -triisocyanate, polymeric MDI, etc. In addition, other urethane prepolymers can also be used. For example, a kind of aliphatic isocyanate And it may be used in combination of two kinds of aromatic isocyanates.

  The said polyol can use the well-known thing normally used for the synthesis | combination of a urethane prepolymer. For example, any one of polyether polyol, polyester polyol, and polyether ester polyol may be used alone or in admixture of two or more.

  Examples of the polyether polyol include polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, and sucrose, or polyhydric alcohols thereof. The polyether polyol which added alkylene oxides, such as ethylene oxide and a propylene oxide, can be mentioned. Polyester polyols are polycondensed from aliphatic carboxylic acids such as malonic acid, succinic acid and adipic acid and aromatic carboxylic acids such as phthalic acid and aliphatic glycols such as ethylene glycol, diethylene glycol and propylene glycol. The polyester polyol obtained in this way can be mentioned. Examples of the polyether ester polyol include those obtained by reacting the polyether polyol with a polybasic acid, or those having both the polyether and polyester segments in one molecule.

  It is more preferable to add a catalyst when the urethane prepolymer is synthesized from the polyol and the polyisocyanate. As a catalyst, the well-known thing normally used for manufacture of a urethane prepolymer can be used. For example, amine catalysts such as triethylamine, triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine, tetramethylguanidine, tin catalysts such as stannous octoate and dibutyltin dilaurate, phenylmercurypropionate or lead octenoate And metal catalysts (also referred to as organometallic catalysts).

  The compound having at least one selected from the group consisting of a vinyl ether group, an allyl ether group, and an acrylate group may be any compound that can be added to the isocyanate group of the urethane prepolymer, such as hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, Examples include allyl ether glycol, hydroxyethyl allyl ether, hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, and the like.

  If the weight average molecular weight of the urethane prepolymer having a plurality of at least one selected from the group consisting of the vinyl ether group, allyl ether group and acrylate group is too low (small), the viscosity of the film forming raw material becomes low, and the resin foam When applied on the surface, the raw material enters the cells (pores) of the resin foam, making it difficult to form a uniform surface coating. On the other hand, when the weight average molecular weight of the urethane prepolymer is too high (large), the strength of the surface coating becomes weak, and the surface coating tends to float from the resin foam when the water-proof sealing material is bent. Accordingly, the weight average molecular weight of the urethane prepolymer having a plurality of at least one selected from the group consisting of the vinyl ether group, the allyl ether group and the acrylate group is preferably 2000 to 30000.

  Examples of the polythiol having a plurality of thiol groups include mercaptocarboxylic acid and polyhydric alcohol esters, aliphatic polythiols, and aromatic polythiols.

  Examples of mercaptocarboxylic acid in the ester of mercaptocarboxylic acid and polyhydric alcohol include thioglycolic acid and meltcaptopropionic acid. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6 -Hexanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol and the like. Examples of the ester of mercaptocarboxylic acid and polyhydric alcohol include, for example, trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), and tetraethylene glycol bis (3-mercaptopropionate). And dipentaerythritol hexa (3-mercaptopropionate).

  Examples of the aliphatic polythiol and the aromatic polythiol include ethanedithiol, propanedithiol, hexamethylenedithiol, decamethylenedithiol, tolylene-2,4-dithiol, and xylenedithiol. In addition, you may use together 1 or 2 or more of the said polythiol. The average number of functional groups of the polythiol is preferably 2.5 or more, and when it is less than 2.5, the adhesiveness and water-stopping property between the resin foam and the surface film are lowered.

  A surface coating material in which a urethane prepolymer having a plurality of at least one selected from the group consisting of the vinyl ether group, allyl ether group and acrylate group and a polythiol having a plurality of the thiol groups is mixed, and at least one side of the resin foam By irradiating the surface coating material with light, a photopolymerization reaction (enthiol reaction) is performed on the surface coating material, thereby curing the surface coating material and forming a skin coating on the surface of the resin foam. The water-proof sealing material can be manufactured.

  The amount of the polythiol is such that the ratio of the total equivalent number of thiol groups of the polythiol to the total number of equivalents of vinyl ether groups, allyl ether groups and acrylate groups of the urethane prepolymer (ene / thiol ratio) is 0.7 to 2. .3 is preferable. When the ene / thiol ratio is less than 0.7 or greater than 2.3, the surface coating material becomes difficult to be cured, and the adhesiveness and water stoppage between the resin foam and the surface coating are lowered.

  In order to effectively perform the photopolymerization reaction by the light irradiation, it is preferable that the surface coating material contains a photopolymerization initiator. Examples of the photopolymerization initiator include acetophenone-based, benzophenone-based, and thioxanthone-based compounds.

Examples of the acetophenone-based photopolymerization initiator include 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 4- (1-t-butyldioxy-1-methylethyl) acetophenone, 2-methyl- 1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, diethoxyacetophenone, 2-hydroxy 2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy- 2-Methyl-1- [4- (1-methylvinyl) phenyl] propaprop Down oligomers, and the like.

Examples of the benzophenone-based photopolymerization initiator include 4- (1-t-butyldioxy-1-methylethyl) benzophenone, 3,3 ′, 4,4′-tetrakis (t-butyldioxycarbonyl) benzophenone, o -Methyl benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxylcarbonyl) benzophenone, 2,4,6- Examples include trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride, and the like. Examples of the thioxanthone series include 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichloro. Examples include thioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3,4-dimethyl-9H-thioxanthone-9-one mesochloride.
The content of the photopolymerization initiator is preferably 0.01 to 5 parts by mass per 100 parts by mass in total of the urethane prepolymer and polythiol.

  As a method for forming a surface coating on the surface of the resin foam in the production of the water-stopping sealing material, the surface coating material is applied to a transparent release film capable of transmitting light at a predetermined thickness by a coating device, and the surface Before the coating material is cured, the resin foam is laminated on the surface coating material, and the surface coating material is cured by irradiating ultraviolet rays from the outside of the release film opposite to the resin foam. Is a method of laminating and integrating the resin foam. Then, if a release film is peeled off, a water-stop sealing material will be obtained. The release film is not particularly limited as long as it can sufficiently transmit light (ultraviolet rays), and examples thereof include polyester resins such as polyethylene terephthalate (PET) and acrylic resins such as polymethyl methacrylate. Moreover, the thickness of a mold release film is not limited, It is hard to tear at the time of peeling etc., and it should just be easy to handle, for example, can mention thickness of 20-200 micrometers.

The irradiation amount of light (ultraviolet rays) at the time of curing the surface coating material is preferably 600 to 1800 mJ / cm ² (in terms of 365 nm). In addition, when the said urethane prepolymer has a vinyl ether group, the irradiation amount of light (ultraviolet rays) can be suppressed to 600-1000 mJ / cm < ² > (365 nm conversion). Moreover, if the thickness of the surface coating after curing is too thin, the water-stopping property will decrease. On the other hand, if it is too thick, depending on the shape of the mounting location of the water-stopping sealing material, Since it becomes difficult to bend, a thickness of about 25 to 2000 μm is preferable. Further, if the elongation of the surface coating is too small, it becomes difficult to bend the water-stopping seal material along the mounting location depending on the shape of the mounting location of the water-proof seal material. K6400-5 compliant) is preferable. Further, the elongation is preferably 500% or less. When the surface coating is easily stretched moderately, when it is pressure-bonded to the surface of the uneven resin foam, it is easy to follow fine bubbles, and adhesion at the interface between the surface coating and the resin foam is increased. In addition, the surface coating and the resin foam can easily follow together when the water-proof sealing material is bent.

[Synthesis of urethane prepolymer]
Using the raw materials shown below, a urethane prepolymer was synthesized with the formulation shown in Table 1.
Polyol a: Polypropylene glycol (PPG), trade name: Actcol D2000 (weight average molecular weight: 2000), Mitsui Chemicals, Inc.
Polyol b: Polypropylene glycol (PPG), trade name: Actcol D1000 (weight average molecular weight: 1000), Mitsui Chemicals, Inc.
Polyol c: Polypropylene glycol (PPG), trade name: Sannix PP-200 (weight average molecular weight: 200), Sanyo Chemical Co., Ltd.
Polyol d: Polypropylene glycol (PPG), trade name: Preminol S4011 (weight average molecular weight: 10,000), Asahi Glass Co., Ltd.
Polyisocyanate; 2,4-TDI / 2,6-TDI = 80/20, trade name: Rupranate T-80 (weight molecular weight: 174.2), BASF INOAC polyurethane
Vinyl ether; hydroxybutyl vinyl ether (weight molecular weight: 116.2), Nippon Carbide Corporation
Allyl ether; hydroxyethyl allyl ether (weight molecular weight: 102.1), Nippon Emulsifier Co., Ltd.
・ Acrylate; 2-Hydroxyethyl methacrylate (weight molecular weight: 130.1), Nippon Shokubai Co., Ltd.

The synthesis of the urethane prepolymer was performed as follows. The amount of polyisocyanate shown in Table 1 is placed in a 1-liter separable flask, stirred while flowing nitrogen, and the amount of polyol shown in Table 1 is dropped.
After completion of dropping, a catalyst (dibutyltin dilaurate, 0.3 g) is added while paying attention to the temperature rise.

  After reacting for 2 hours, sampling was performed, and the isocyanate group content was urethane prepolymers A, B, C: 4.0 to 5.0%, urethane prepolymer D: 2.0 to 3.0%, urethane prepolymer It is confirmed that the polymer E is 0.5 to 1.0% and the urethane prepolymer F is 0.2 to 1.0%. When it is not within the range of each isocyanate group content, the reaction time is extended. The measurement of the isocyanate group content is performed according to a method based on JIS Z1603-1: 2007 (polyurethane raw material aromatic isocyanate test method).

Next, vinyl ether, allyl ether, and acrylate are dropped according to the composition shown in Table 1 and reacted for 2 hours. After the reaction, sampling is performed to confirm that the isocyanate group content is 0.5% or less. When the content is 0.5% or less, the reaction is completed, and the products are urethane polymers A to F.
In addition, the theoretical molecular weight of each urethane prepolymer in Table 1 was calculated from the structural formula.

[Creation of UV (ultraviolet) curing surface coating material]
The following polythiols were mixed with urethane prepolymers according to the formulations in Tables 2 and 3 to prepare UV curable surface coating materials.
Polythiol A; butanediol bisthiopropionate, trade name: BDTP (weight molecular weight: 266.4), Sakai Chemical Co., Ltd.
Polythiol B: Trimethylolpropane tris, trade name: TMMP (weight molecular weight: 398.5), SC Organic Chemical Co., Ltd.
Polythiol C: Pentaerythritol tetrakis, trade name: PEMP (weight molecular weight: 488.6), SC Organic Chemical Co., Ltd.
Polythiol D: Dipentaerythritol hexakis, trade name: DPMP (weight molecular weight: 783.0), SC Organic Chemical Co., Ltd.
The average number of functional groups of the thiol group that reacts with the urethane prepolymer is shown in the column of [Average number of functional groups] in Tables 2 and 3. The ratio of the total number of all thiol groups to the total number of equivalents of the vinyl ether group, allyl ether group or acrylate group of the urethane prepolymer is shown in the [En / thiol ratio] column of Tables 2 and 3.

[Manufacture of water-proof sealing materials]
A UV curable surface coating material is supplied from a coating die at a temperature of 80 ° C. onto a transparent release film having a thickness of 50 μm, and stretched by a doctor blade to form a coating film having a thickness of 50 μm. The release film used is a polyethylene terephthalate (PET) film (trade name: E7006, Toyobo Co., Ltd.) that transmits ultraviolet rays.

A soft polyurethane foam having an open cell structure with a thickness of 10 mm (number of cells: 55 cells / 25 mm, density: 28 kg / m ³ , trade name: EKS, Inoac Corporation) is placed on the surface of the coating film and separated. UV curable surface coating material is irradiated from the mold film side with an ultraviolet ray irradiation device (trade name: ultraviolet ray irradiating device Eye Graphics Co., Ltd.) with an irradiation amount of 600 to 500 mJ / cm ^2. Is cured. Thereafter, the release film is peeled off to obtain a water-proof sealing material.

  Examples 1 to 4 are examples in which the polythiol used in combination with the urethane prepolymer A is different. Example 1 is an example using urethane prepolymer A and polythiol C, Example 2 is an example using urethane prepolymer A, polythiol A and polythiol B, and Example 3 is an example using urethane prepolymer A and polythiol B Example 4 is an example using urethane prepolymer A and polythiol D.

Examples 5 to 9 are examples in which the urethane prepolymer combined with the polythiol C was varied. Example 5 is an example using urethane prepolymer B and polythiol C, Example 6 is an example using urethane prepolymer C and polythiol C, Example 7 is an example using urethane prepolymer D and polythiol C, Example 8 is an example using urethane prepolymer E and polythiol C, and Example 9 is an example using urethane prepolymer F and polythiol C.
Example 10 and Example 11 are examples in which the ene / thiol ratio is different.

  Comparative Example 1 is a combination of urethane prepolymer A and polythiol A, an example having an ene / thiol ratio of 1, Comparative Example 2 is a combination of urethane prepolymer A and polythiol C, an example having an ene / thiol ratio of 0.5, a comparative example 3 is an example of a combination of urethane prepolymer C and polythiol C, with an ene / thiol ratio of 2.5. Comparative Example 4 is an example of urethane prepolymer A only, and Comparative Example 5 is an example of urethane prepolymer C only.

  About each Example and each comparative example, the water-stop test and the adhesiveness test of a surface film and a resin foam were done. In addition, since the comparative example 4 which consists only of urethane prepolymer A did not harden | cure, the water-stop test and the measurement of the adhesiveness of a film | membrane and a resin foam were not performed.

The water-stop test will be described. First, a 200 mm × 200 mm × 10 mm sample for punching was prepared for each example and each comparative example, and a double-sided adhesive tape (manufactured by Nitto Denko, product name: No. 5000) was attached to the surface opposite to the surface coating. Thereafter, a test piece is produced by punching into a U-shape having the dimensions shown in FIG.
Next, in the two acrylic resin plates having the dimensions shown in FIG. 2, a polypropylene (PP) film (thickness 25 μm) and a spacer (thickness 5 mm) are set on the surfaces facing each other, and the surface of the polypropylene film is washed with alcohol. To do. Place the double-sided adhesive tape side of the test piece on the polypropylene film surface of one acrylic resin plate, then cover the other acrylic resin plate so that the polypropylene film is on the test piece side, tighten the four corners with wing nuts, The thickness of the test piece is set to 5 mm (50% compression). Next, distilled water is poured into the U-shaped test piece so that the water head height (water level) is 100 mm. After completion of the injection, water leakage after 12 hours (h) and 24 hours (h) was confirmed, and when there was no water leakage, it was judged as pass (◯) and when there was water leakage, it was judged as unacceptable (x). The measurement results are shown in the water-stop column of Tables 2 and 3.

  In the adhesion test between the surface coating and the resin foam, the release film is peeled off from the water-repellent foam material after the surface coating raw material is cured with ultraviolet rays, and the cured surface coating remains as an adherent on the release film. Judged whether or not. When the surface film did not adhere to the release film, it passed (◯), and when it adhered, it was determined to be rejected (x). The presence or absence of deposits was confirmed visually. The test results are shown in the membrane-resin foam adhesion column of Tables 2 and 3.

Moreover, only the surface film of each Example and each comparative example was manufactured separately from manufacture of each Example and each comparative example. That is, after the surface coating material of each example and each comparative example was applied to the release film in a thickness of 50 μm, the surface coating material was irradiated with ultraviolet rays at a dose of 600 mJ / cm ² without laminating the resin foam. Is cured and then peeled off from the release film to form a surface coating. Using the obtained surface coating, the elongation (%) of the surface coating was measured according to JIS K6400-5. The results are shown in the film elongation (%) column of Tables 2 and 3.

In each of Examples 1 to 11, the water stopping performance was acceptable (◯), and the adhesion between the surface coating and the resin foam was also acceptable (◯).
On the other hand, in Comparative Example 1 in which the average number of functional groups of polythiol was 2 and the ene / thiol ratio was 1, the elongation of the film was 800%, but both the water-stopping property and the film-resin foam adhesion were not acceptable. It was. In Comparative Example 2 in which the average number of functional groups of polythiol was 4 and the ene / thiol ratio was 0.5, the elongation of the surface film was 400%, but the water-stopping (24h) and membrane-resin foam adhesion were Was also rejected. In Comparative Example 3 in which the average number of functional groups of polythiol was 4 and the ene / thiol ratio was 2.5, the elongation of the surface film was 200%, and the film-resin foam adhesion was acceptable, (24h) was a failure. In Comparative Example 4 containing only the urethane prepolymer A and no polythiol, the surface coating material was not cured and the surface coating was not formed. The comparative example 5 which contains only the urethane prepolymer C and does not contain polythiol had only 70% elongation of the surface film, and both the water-stopping property and the film-resin foam adhesion were unacceptable.

  As described above, the water-proof sealing material of the present invention has sufficient adhesion between the resin foam and the surface coating on the surface of the resin foam, and has high water-stopping properties.

Claims (3)

In a water-stop sealing material comprising a resin foam and a surface coating provided on at least one surface of the resin foam,
The surface coating is a photopolymerization reaction cured product of a urethane prepolymer having a plurality of at least one selected from the group of vinyl ether groups, allyl ether groups and acrylate groups, and a polythiol having a plurality of thiol groups,
The average functional group number of the polythiol is 2.5 or more,
The ratio of the total equivalent number of thiol groups possessed by the polythiol to the total equivalent number of vinyl ether groups, allyl ether groups, and acrylate groups possessed by the urethane prepolymer is 0.7 to 2.3. Seal material.   The water-proof sealing material according to claim 1, wherein the urethane prepolymer has a weight average molecular weight of 2000 to 30000. The water-stop sealing material according to claim 1 or 2, wherein the elongation of the surface coating is 100% or more.

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